Mutations in the SETX gene are associated with a rare and autosomal dominant form of JALS, also known as ALS4, which is characterized by motor neuron dysfunction of early onset, slow progression, acute muscle weakness and pyramidal tract signs, and the absence of bulbar and sensory abnormalities (Orban et al., 2007). The gene discussed is SETX; the disease is juvenile amyotrophic lateral sclerosis.